The objective of the present investigation is to gain basic information on the sequence and mechanism of the respiratory chain-linked energy transduction and the structure function relationship of mitochondrial inner membrane by studying various types of the respiratory chain-linked electron and energy transfer reactions in a bovine cardiac submitochondrial membrane system and by resolution and reconstitution of individual components essential for the respiratory chain-linked electron and energy transfer reactions. We plan to employ the following approaches. (1) Elucidation of the mechanism of the oligomycin-induced respiratory control by studying various biochemical and biophysical parameters of the membrane preparations recently achieved in our laboratory. (2) Application of extrinsic probes for the study of membrane conformation and/or state change. Continued effort on the environmental sensitive probes, quinacrine for membrane proton content and 8-anilinonaphthalene sulfonate for membrane hydrophobicity will be made. Special attention will be made on the interaction between the probe molecules and the membrane component(s). Derivatives of these probes will be made and investigated. Exploration for new probes is also planned to be made. (3) Modification of submitochondrial membranes with respect to its lipid and protein content will be made and characterized. (4) Elucidation of the organization of the functional components and their association in the mitochondrial inner membrane by means of resolution and reconstitution. This type of attack should expose the inadequacies of the existing hypotheses and theories, lead to new theories, and clarify the delicate organization of the mitochondrial energy transfer system and ultimately lead to the understanding of the regulation of the mitochondrial energy metabolism in both healthy and diseased cardiac muscle.